The Dietary Education Trial in Carbohydrate Counting (DIET-CARB Study in Type 1 Diabetes

The Dietary Education Trial in Carbohydrate Counting (DIET-CARB Study): A Randomized, Parallel, Open-label, Intervention Study Comparing Different Approaches to Dietary Self-management in Patients With Type 1 Diabetes

The study is designed to evaluate two different dietitian-led self-management approaches in carbohydrate counting compared to routine dietary care (control) on glycaemic control in adult patients with type 1 diabetes:

1. The basic carbohydrate counting concept aims at improving carbohydrate counting accuracy and day-to-day consistency of carbohydrate intake (the BCC intervention)
2. The advanced carbohydrate counting concept aims at improving prandial insulin dose accuracy using an automated bolus calculator (the ABC-ACC intervention)

The main hypothesis is that structured training and education in either the BCC concept or the ABC-ACC concept will reduce HbA1c or the average glucose variability more than routine dietary education.

The current study is a randomized controlled trial with a parallel-group design. A total of 231 patients will be enrolled in the trial. Participants will be randomized to one of three arms: 1) Basic carbohydrate counting (BCC), 2) Advanced carbohydrate counting with an automated bolus calculator (ABC-ACC), or 3) Standard dietary care.

The primary objective is to evaluate the six months effects of education in the BCC concept and the ABC-ACC concept compared to standard dietary care on glycaemic control as assessed by HbA1c or MAGE (mean amplitude of glycaemic excursions).

Inclusion Criteria:

• Type 1 diabetes
• Diabetes duration; >12 months
• HbA1c of 53-97 mmol/mol
• Multiple daily insulin injection therapy
• Provided voluntary written informed consent

Exclusion Criteria:

• Practicing carbohydrate counting, as judged by the investigator
• Participated in a BCC group program within the last two years
• Use of insulin pump, or plans of having an insulin pump within the study period
• Fixed dose of rapid acting insulin therapy for meals
• Split-mixed insulin therapy
• Use of open CGM
• Use of Freestyle Libre
• Use of an automated bolus calculator
• Gastroparesis
• Pregnancy or breastfeeding, or plans of pregnancy within the study period
• Low daily intake of carbohydrates (defined as below 25 E% or 100 g/day), as judged by the investigator
• Uncontrolled medical issues, as judged by the investigator or a medical expert
• Concomitant participation in other clinical studies
• Unable to understand the informed consent and the study procedures